Internal combustion engine



Jan 19, 1943. w. D. TIPTON INTERNAL COMBUSTION ENGINE 4 Sheets-Sheet 1Filed Sept. 2]., 1942 wzziwmlwm 530 w. D. TEPTON 2,308,839

INTERNAL COMBUSTION ENGINE Filed Sept. 21, 1942 4 Sheets-Sheet 2 Jan.19, 1943. w. D. TIPTON I 2,308,839

4 INTERNAL COMBUSTION ENGINE Fil'ed se' y. 21, 1942 4 Sheets-Sheet 3 Mom1 I Patented Jan. 19, 1943 'UNITED STATES PATENT OFFICE zsoasss INTERNALCOMBUSTION ENGINE William 11.1mm, Stbneleigh, Md. Application September:1, 1942, Serial No. 459,164 21 Claims. (Cl. 123-190) This inventionrelates to rotary valve internal combustion engines.

The many advantages of rotary over reciprocating valves for internalcombustion engines have been known in the art for .many years. As setforth in prior patents of the present inventor, No. 2,158,442, dated May16, 1939, and No. 2,216,057, dated September 24, 1940, these advantagesinclude more positive actuation, greater accuracy in timing, feweroperating parts, ease of adjustment, reduced size and weight per horsepower, elimination of hot spots and avoidance of pre-ignition. Many ofthese advantages are becoming more and more compelling, particularly inconjunction with aircraft engines, as demands upon their power outputand speed of operation are increased.

It is now sought to combine these advantages of rotary valve actuationwith the principles of multiple combustion in such a manner as to retainthe most desirable inherent characteristics of each. By the use ofsupplemental or auxiliary combustion chambers which are caused tocommunicate with the main combustion chamber after ignition hasoccurred, peak pressures can be reduced with a corresponding decrease inshock, the duration of the reduced peak pressures can be increasedresulting in the application of appreciable forces at more eflectivecrank angles,

and the power and eificiency of an engine of given size and weight canbe increased.

In applying the engine of the present invention to aircraft propulsionparticularly, the desirability of maximum power for take-off and maximumefi'lciency at partial throttle r cruising speed has ume 01' one or moreauxiliary combustion chambers is proposed in others. Where automaticcontrol of auxiliary combustion chamber volume is 4 they may be made tocommunicate in stages,

singly or in groups, with the main combustion chamber by appropriatetiming. The valve or valves for this engine may be provided with sealingmeans responsive to combustion chamber pressures, and such valves mayassume the form of the so-called cuff type having an outwardly divergentperiphery. The main valve may be fitted with a replaceable element todetermine the volume of the combustion chamber. Moreover, the auxiliarycombustion chamber or chambers may be supportedby the valve itself Wheresuch disposition is preferred to mounting upon or within the cylinderwalls or head. The valve or valves are preferably lubricated in such away as .to take advantage of centrifugal forces in distributing thelubricant. The valve or valves may be driven by gearing applied near thehead of the respective cylinder to avoid as far as possible the adverseeiiects of heating.

A more complete understanding of the present invention and its objectswill follow from a detailed descriptionof the accompanying drawingswherein:

Fig. 1 is a sectional elevation, partiallybroken I away, of a cylinderembodying certain features of received considerable attention. Theseresults f can be more nearly achieved by reducing .the-yoI ume of theauxiliary combustion chamber or chambers at partial throttle, thusincreasing the expansion ratio, and thereby increasing'the value ofthermal efllciency as expressed in the relationship based upon the wellknown Otto cycle.

In accordance with the objects of this invention, an internal combustionengine will have each cylinder provided with a piston to define acombustion chamber with which one or more auxiliary combustion chamberscooperate, together with-rotary valve means controlling the passage-offluid to and from the combustion chambers. Rotary valves for the mainand auxiliary combustion chamber may be independent, integral orcoupled. Adjustable means for controlling the passage of fluid betweenthe combustion chambers is likewise contemplated in' conjunction withthe valve means in some instances, while means for varying thevoloperating gear; and

the present invention;

Fig. 2 is a section taken along line 2-2 of Fig. 1; Fig. 3 is a sectiontaken along line 33 of Fig. 1; 4 is a sectional elevation of a cylinderhead depicting a modification; Fig. 5 is a sectional elevation of acylinder he illustrating another modification;

Fig; 6 is a. sectional elevation showing still another modification;

Fig. 7 is a diagrammatic representation of a v 7 portion, of a operatinggear;

Fig. 8 is a. diagrammatic showing of additional Fig. 9 is a curve sheetillustrating the timing and performance of an engine conforming. to

the present invention. 1

The portion of an engine shown in Fig. 1 includes a finned cylinderhaving a finned head 22' attached thereto. by means of suitable bolts24. A cylinder sleeve 25 is threaded into the cylinder for reception ofa piston 28 which reciprocates therein. The outer end of the cylinder isprovided with an outwardly divergent frustoconical seat so into which isfitted a rotary valve fsigned to produce forces upon the valves justsuflicient to prevent leakage ofthe gases and asoaeso ing areas of thevalves to produce the most desirable bearing pressure of the valves upontheir seats. Thus, thesealing element may .be dethereby avoid excessivefriction between the valves and their seats. It will be noted that thesealing element is arranged between two memas containing a plurality ofauxiliary combustion chambers 46, the number and volume of which may beselected in accordance with the desired characteristics of the engine.Figs. 1 and 3 of the drawings for purposes of this description however,six such auxiliary chambers have been depicted, having an aggregatevolume approximating one-third of the total combustion chamber volume.Since .it ;i s desirable to maintain the maximum usable com- I pressionpressure at cruising power for aircraft engines, which is usuallyfromabout 50% to As depicted in.

bers which rotate together and accordingly is subjected to no mechanicalwear.

In lubricating the valves of the construction shown in Fig. 1, advantageis taken of the centrifugal force developed by their rotation. Oil isfed from the crankcase or other suitable source through the bore 16 ofthe hollow shaft 10 to portions of the valves approaching their axes. Inthe case of the cuff valve 32, oil from the bore of shaft 10 passesthrough registering transverse ports penetrating the walls of the innershaft about 50% full power, it may be desirable to 'de-- sign the volumeof these auxiliary chambers so that when deducted from the totalcombustion A chamber volume, there remains such a; volume as willprovide maximum compression pressures at the most desirable cruisingpower'factor. Such design' will provide a maximum expansion ratio forcruising purposes, and since efllciency of an internal combustion engineis a function of the expansion ratio, it will follow that an increasedefliciency may beeffected by thus increasing 1 the compression ratio.

Communication between the auxiliary combustion chambers, and the maincombustion chamber is controlled in timed relationship by means of avalve 48, generally of the disk'type, superposed upon the main valve 32and containing a plurality of ports 50, corresponding in number to thenumber of auxiliary combustion chambers, depicted as broken circles inFig. 3 of the drawings. The disk valve 48 is coupled to the cuff valve32 by means of an appropriate number of pins 52 fitted into registeringapertures formed in the opposed surfaces of the two valves. Theperiphery of the disk valve is pro- III, the outer shaft 80 and thebearing 18 for the outer shaft, to a bore 80 provided in the cylinder'wall, which terminates in a groove 82 communieating with the face ofthe cuif valvenear its reduced end."v 'Upon rotation of the valve,lubricant will flow outwardiy due to centrifugal foi' 'ceuntil itreaches the pin'ions 58 and-68, whereupon r it will flow along the outersurfaces of theshafts .68 and." back outer-end of the bore 16 formed inthe shaft 1'0 communicates with a passage 84 provided in the cylinderhead to deliver oil substantially ce'nvided with an outwardly directedannular flange 54 on which gear teeth 56 are formed for cooperation witha pinion 58-carriedby a hollow shaft 88 which is driven in synchro'nismwith the engine crank shaft in the manner diagrammatically representedin Fig. 'l of the drawings.

Interposed between the cylinder head 22 and the disk valve '48, there isprovided a second disklike valve 62, likewise having an outwardlydirected annular flange 64 provided with teeth 6G for-engagement withthe teeth of a pinion 88 carried by a hollow shaft 10 which extendsthrough the hollow shaft 60 and which may be actuated manually orautomatically in a man- 'ner to be described. The disk-like valve 82 islikewise providedwith a plurality of ports 12 corresponding in number tothe number of auxiliarycombustion chambers. These ports :are

' depicted in broken lines as having a trapezoidlike outline in Fig. 3of the drawings.

trally of the upper face of the disk valve 48.

Here again centrifugal force will. distribute the lubricant towards theperiphery of the valve into the gear housing 86 and back to thecrankcase.

It will follow from the foregoing description that the-disk -likevalve62 may be actuated .to permit or discontinue communication between theauxiliary combustion chambers and the main combustion chamber. When theports 12 of this valve register with those of the auxiliary combustionchambers, the full combustion volume of the engine will be utilized toproduce full power. On the other hand, when the valve is rotated bymeans of the shaft 10 to interrupt communication, only the maincombustion chamber is utilized, a condition contemplated for cruising in1 connection with aircraft engines.

Assuming that the disk-like valve 82 is positioned to permit theauxiliary combustion chambers to cooperate with the main combustionchamber, the comparative results will be depicted in th curvesof Fig. 9..These curves have been plotted to compare the operation'of theengine ofthe present invention with the operationof the well known 'WrightCyclone engine'having poppet valves. The time-pressure curves include Ia full. line curve representingthe cycle of the standard selected, and abroken lin curve illustrating the cycle of the present invention. The

time-area curves depict the opening and closing of the poppet valvesofthe standard engine in In order to seat the cuff valve 32 and the diskvalve 48 in response to combustion chamber pressures with a forcesufllclent to prevent leakage, an expansible substantially U'-shapedsealing element .14 is interposed between the adjacent faces of the twovalves. This sealing element may be designed with respect to theseatbroken lines, as'compared with the opening and closing of'the rotarvalves of the present invention in full-lines. Also shown on the basisoi the time-area relationship is a solid .ine curve,

appropriately identified, illustrating theopening and closing of theauxiliary combustion chamber" ports. With reference to'the time-areacurve for the auxiliary chambers, it will be noted that they are closedto the main chamber five degrees before ignition and remain closed whilecombustion occurs in th main chamber, whereupon opposed pairs of theauxiliary chambers, indicated by the letters A, B and C, are opened tothe main chamtowards the crankcase. nTheasoaaao 3 ber at ten-degreeintervals of crankshaft travel and their contents ignited in thatsequence. This delayed ignition serves to produce a. continuation of thetime-pressure curve for combustion as indicated by the broken line curveplotted. on the time-pressure coordinates! j The valve of thisconstruction has been geared to rotate at one-fourth crankshaft, so asindicated by the curves, the auxiliary combustion chambers communicatewith the main combustion chamber three times in each cycle, oneclosingoccurring at about top dead center on the firing stroke and the othertwo at the closing of by a plurality of pins 12a secured inthe head bynuts I30.

chamber and rotary valve of the type illustrated in Fig. l.

" In Fig.- 7 of the drawings. a suitable operating mechanism has beenshown diagrammatically.

the exhaust port and the opening of the inlet ports. Three closings ofthe auxiliary chambers have been selected, since two of the closings,not being required for functioning of the auxiliary combustion cycle,will occur at points which wil not interfere with the total combustioncycle.

By utilizing a plurality of auxiliary chambers and a correspondingnumber of valve ports, the ratio of portarea to auxiliary chamber volumecan be made as great as possible. The modification depicted in Fig. 4 ofthe drawings contemplates a plurality of auxiliary combustion chambers88, the volume of which may be adjusted, manually or automatically toconform with de sired operating conditions. The disk valv 48. like thatof the preceding example, will be driven by a suitable pinion in timedrelationship with the crankshaft to effect communication between theauxiliary combustion chambers and the main combustion chamber at thedesired intervals. In lieu of the disk-like valve.62 of the precedingexample however, this form of the invention utilizes an annular member90, which is substantially s-shaped in section, provided with externalteeth 92 for cooperation with a suitable pinion like pinion 58 of thepreceding example, and internal teeth 94 for engagement with teeth 96formed ,on the lower ends of sleeves 98 rotatably mounted in sockets Iformed in the head I02. These sleeves contain the auxiliary combustionchambers which are provided with internal threads I04 extending over asubstantial portion of their lengths for cooperation with externallythreaded plugs I06. These plugs are longitudinally movable with respectto the sleeves, but maintained non-rotatable with respect thereto bymeans of splines I08 carried by pins IIO which are held fast withrespect to the head by means of keys I I 2 and nuts I I4 threaded uponthe ends of the pins. A gear cover plate IIG, suitably dowelled to thecylinder head so as to prevent rotation of said cover plate, isinterposed between the disk valve 48 and the toothed ends of the sleevesto prevent gas leakage into the gear recesses. It will be evident thatupon rotation of the annular member 90, the sleeves 98- will be rotatedand the plugs I06 will be advanced or retracted, depending upon thedirection of rotation, to reduce or enlarge respectively, the volume ofthe auxiliary combustion chambers. The provision of a single auxiliarycombustion chamber having an adjustable volume is illustrated in Fig. ofthe drawings. In this case,

the head I02 is formed with an annular recess II8 containing aninternally threaded sleeve I20,

. having a flange I22 at its inner end terminating in teeth I24 whichcorrespond with the teeth 92 described in connection with Fig. 4 of thedrawings. An annular plug I26 is externally threaded for cooperationwith the sleeve I so that it may be advanced or retracted by rotation ofthe sleeve. The plug is restrained-against rotation The disk valve 48and its gearing is driven by the hollow shaft 50, the lower end of whichterminates in a bevel gear I32 which engages a. cooprating bevel gearI34 which is loosely mount- -edfor rotation upon the crankshaft I36. The

bevel gear I34 is driven at the desired reduced rate with respect to thecrankshaft by means of a spur I38keyed to the crankshaft, throughcooperating gears I40 and I42. The pinion 68 for driving the disk-likevalv of Fig. 1 or the gears of Figs; 4 or 5 is mounted on the shaft I0whose lower end carries a bevel gear I44 engaging with a bevel gear I46loosely journalled on the crankshaft I35. A control element I48 isconnected through a link I50 to a point on the bevel gear I46 to producethe desired rotation.

Where automatic control of the auxiliary combustion chambers iscontemplated, it may be preferable that the volume of these chambers bevaried directly as a function of absolute manifold pressure which willrender the actuation independent of atmospheric pressure and altitude.

This may be accomplished by apparatus of the type disclosed in Fig. 8 ofthe drawings wherein the bevel gear I46 through the link I50 isconnected with a piston I52 which is received in a cylinder I54. Oneside of the piston is loaded by a spring I55 while the other surface issubjected to engine oil pressure admitted through an inlet I58. The endof the cylinder which receives the oil is provided with a partition I 50through which a follow-up tube I62 extends in fluid-tight relationshipby means of suitable packing. The follow-up tube also extends throughthe opposite end of the cylinder where it is also provided with suitablefluid-tight packing and thence to an aneroid control device I10. Thepartition I prevents the egress of oil except through the open end ofthe follow-up tube I68 which is normally closely adjacent the pistonI52. When the engine is running, the oil entering the cylinder will movethe piston I52 against the force of the spring I56 and flow through theend of the follow-up tube of the servomotor to a transverse port I72provided in the tube on the opposite side of the partition and throughan outlet H4 in the cylinder to a suitable reservoir. Thus it will beclear that the piston will automatically position itself at a slightdistance from the end of the follow-up tube.

The aneroid control I10 includes a piston I16 received in a cylinderI18, subjected to inlet manifold pressure on one side through a, port Iprovided in the cylinder and to the force of a spring I82 enclosed in anevacuated closed bellows I84 on the other side. Accordingly, the pistonI16 of the aneroid control will respond to the absolute manifoldpressure to adjust the follow-up tube I68 so that the piston I52 of thehydraulic booster will always follow the motion of the piston I16 andimpart this motion to the bevel gear I46 and ultimately to the controlof the auxiliary combustion chambers themselves.

In the modification shown in Fig. 6 of the drawings, the auxiliarycombustion chamber or chambersIBG will be formed in the filler block 7I94 froma pinion, not shown,

44 carried by the valve 32. In this case, a valve plate I88 is heldagainst rotation bythehead I90 and is provided with a suitable numberports, not shown, to time communication between the main combustionchamber and the auxiliary combustion chamber or chambers. A sealingelement I92 is interposed between the valve plate and the head to imposepressures of a desired magnitude between the valve plate I88 and itsseat on the valve 32 on the one hand and between valve 32 and its seaton the cylinder wall on the other.

similar to the pinion 58. of Fig. 1, the gear I94 being looosely splinedor otherwise coupled to the outer end of the valve to permit somefreedom of movement to compensate for expansion due to heating.

Upon reference to Fig. 2 of the drawings, it will be noted that bushingsI96 for the reception of spark plugs are located at the side of the com-The valve 321s driven by a gear bustion chamber so as to be masked bythe valve until the ignition point has been reached, whereupon they willbe uncovered. Being 'thus exposed to combustion temperatures for shortperiods only, the spark plugs will be maintained at minimumtemperatures. Also shown in this fi ure are twin inlet portsdiametrically opposed and a single exhaust port. Only one exhaust porthas been shown to simplify maniiolding,

and consequently the port has been made sum ciently large to satisfyoperating requirements. Its time-area curve as shown inFig. 9 of thedrawings, conforms substantially to that of the standard engine. On theother hand, the timearea curve for the intake ports indicatesconsiderably more area than is made available by the poppet valve designoi the standard selected.

From the foregoing description, various additional modifications havesuggested themselves to the inventor and some of these may likewiseocour to others skilled in the art. Accordingly, it

- should be borne in mind that the real scope of the invention is to bemeasured not by these examples but by the appended claims.

I claim: 1. An internal combustion engine comprising a cylinder havinga'piston fitted'therein to define a combustion chamber, an auxiliarycombustion chamber periodically closed with respect to said combustionchamber, and rotary valve means between said chambers and controllingthe passage of fluid to and fromsaid cylinder and said auxiliarycombustion chamber.

2. An internal combustion engine comprising a cylinder having a pistonfitted therein to define a combustion chamber, an auxiliary combus tionchamber cooperable with said combustion chamber, and rotary valve meansbetween said chambers and controlling the passage of fluid between, toand from said cylinder and said auxiliary combustion chamber.

3. An internal combustion engine comprising a cylinder havinga pistonfitted therein to deline a combustion chamber, an auxiliary combustionchamber cooperable with said combustion chamber, rotary valve meanscontrolling the passage of fluid to and from said cylinder and saidauxiliary combustion chamber, and adjustable means independent of saidvalve means for controlling the passage of fluid between said cylinderand said auxiliary combustion chamber.

- 4. An internal combustion engine comprising a cylinder having a pistonfitted therein to define a combustion chamber, an auxiliary combustionchamber cooperable with said combustion chaming a cylinder having a headand a piston fitted means for varying the volume of said auxiliarycombustion chamber.

5. An internal combustion engine comprising a cylinder having a pistonfitted therein to define a combustion chamber, an inlet manifoldcommunicating with said cylinder, an auxiliary combustion chambercooperable with said combustion chamber, rotary valve means controllingthe passage oi fiuidto and from said cylinder and said auxiliarycombustion chamber, and means responsive to absolute inlet manifold pressure for varying the volume of said auxiliary combustion chamber.

6. An internal combustion engine comprising a cylinder having a pistonfitted therein to de-' fine a combustion chamber, a plurality ofauxiliary combustion chambers adapted to communicate with saidcombustion chamber in predetermined sequence, and rotary valve meanscontrolling the passage 01! fluid to and from said passage of fluidbetween, to "and'from said cylinder and said auxiliary combustionchamber, and

cylinder. and said auxiliary combustion chamof fluid to and from saidcylinder, and means for controlling fluid passage between said cylinderand said auxiliary combustion chamber.

8. An internal'cqmbustion engine comprising a cylinder havinga head anda piston fitted therein to define a combustion chamber, an auxiliarycombustion chamber cooperable with said combustion chamber, saidcylinder providing an outwardly divergent valve seat near its head end,a rotary valve fitted trolling the passage of fluid to and from saidcylinder, and a rotary valve coupled to the first said valve forcontrollingfiuid passage between said cylinder and said auxiliarycombustion chamber.. j

9. An internal combustion engine comprising a cylinder. having ahead anda piston fitted therein to define a combustion chamber, an auxiliarycombustion, chamber cooperable with. said to said seat for concombustionchamber, said cylinder providing an responsive to combustion chamber andauxiliary combustion chamber tween said valve and said head.

10. An internal combustion engine compristherein to define'a combustionchamber, an

auxiliary'combustion chamber cooperable with .tween said valves.

said combustion. chamber, said cylinder providing an outwardly divergentvalve seat near its head end, a rotary valve fitted to said seat forcontrolling the passage offluid to and from said cylinder, a rotaryvalve superposed upon the first said valve for controlling fluid passageand said auxiliary com- 1 between said cylinder bustion chamber, andsealing means responsive to combustion chamber pressure interposed be-11. An internal combustion engine comprising pressure interposed beacylinder having a head and a piston fitted therein to define acombustion chamber, said cylinder providing an outwardly divergent valveseat near its head end, a rotary valve fitted to said seat forcontrolling the passage of fluid to and from said cylinder, and areplaceable element received by said valve to determine the volume ofsaid combustion chamber.

12. An internal combustion engine comprisin a cylinder having a pistonfitted therein to define a combustion chamber, an auxiliary combustionchamber cooperable with said combustion chamber, a rotary valve forcontrolling the passage of fluid to and from said cylinder, a secondrotary valve for controlling the passage or fluid chamber, and rotaryvalve means supporting said auxiliary combustion chamber and controllingthe passage of fluid to and from said cylinder and said auxiliarycombustion chamber.

14. An internal combustion engine comprising a cylinder having a headand a piston fitted therein to define a combustion chamber, a pluralityof auxiliary combustion chambers carried by said head and cooperablewith said combusation with said combustion chamber.

16. An internal combustion engine comprising a cylinder having a pistonand rotary valve means fitted therein to define a combustion chamber.and an auxiliary combustion chamber carried by said valve means andcooperable with said combustion chamber, said rotary valve meanscontrolling the passage 01 fluid to and from said cylinder and'saidauxiliary combustion chamber.

17. An internal combustion engine comprising a cylinder having a head, apiston and a rotary valve fitted therein to define a combustion chamber,an auxiliary combustion chamber carried by said valve and cooperablewith said combustion I chamber, said rotary valve between said chambarsand controlling the passage ot-fiuid to and from said cylinder and saidauxiliary-combustion chamber, and sealing means responsive to combustionchamber and auxiliary combustion chamber pressure interposed betweensaid valve and said head.

18. An internal combustion engine comprising a cylinder having a headand a piston fitted therein to define a combustion chamber, an auxiliarycombustion chamber cooperable with said combustion chamber, saidcylinder providing an outwardly divergent valve seat near its head end,rotary valve means bettveensaid chambers and fitted to said-seat, andcontrolling the passage of fluid to and from said cylinder and saidauxiliary combustion chamber, means for driving said valve meansadjacent its outer end and means for delivering lubricant to said valvemeans at a point near its smaller end.

19. An internal combustion engine comprising a cylinder having a headand a piston fitted therein to define a combustion chamber, an auxiliarycombustion chamber carried by said head and cooperable with saidcombustion chamber, said cylinder providing an outwardly divergent valveseat near its head end. said head providing a valve seat for saidauxiliary combustion chamber, rotary valves fitted to said seats forcontrolling the passage of fluid to and from said cylinder and saidauxiliary combustion chamber, and driving means for said valves engagedtherewith near the head end of said cylinder.

20. An internal combustion engine comprising a cylinder having a pistonfitted therein to define a combustion-chamber, an auxiliary combustionchamber cooperablewith said combustion chamber, rotary valve meanscontrolling the passage of fluid to and from said cylinder and saidauxiL iary combustion chamber, and means for introducing lubricant tosaid valve means at a point of relatively small diameter so that thelubricant will be distributed by centrifugal force upon rotation of saidvalve means. v

21. An internal combustion engine comprising a cylinder having a head, apiston and a rotary valve fitted therein to define a combustion chamber,an auxiliary combustion chamber adjacent to and cooperable with saidcombustion chamber, said rotary valve controlling the passage of fiuidto and from said cylinder and said auxiliary combustion chamber, andsealing means responsive to combustion chamber and auxiliary combustionchamber pressure interposed between said valve and said head. WILLIAM D.TIPTON.

